Conventionally, speaker enclosures are typically made of wood material having a rectangular shape. The range of speaker enclosures in the market are varied and are used for applications ranging from home use to professional use, including but not limited to outdoor performances.
Typically, the speaker enclosures used for professional use are generally large and heavy. The weight and bulk of the speaker enclosures make transportation and movement difficult. Apart from the weight, the materials used for speaker enclosures affect the sound performance of the speaker by absorbing vibrations. Speaker enclosures made of different material such as plywood, birch or Medium-Density Fibreboard (“MDF”) have different degree of effectiveness in absorbing undesirable vibrations. Such damping materials have been used internal of the speaker enclosures to reduce undesirable vibrations.
The panels for forming the speaker enclosure prevent sound waves generated by the rearward facing speaker driver interacting with sound waves generated at the front of the speaker driver, such forward and rearward-generated sound waves are out of phase with each other, any interaction between the two sound waves in the listening space creates distortion of the original sound waves as they were intended to be reproduced. It thus avoids internal standing sound waves. Such panels help to prevent distortion of the sound produced by the speakers and prevent the magnification of unwanted frequencies causing undesirable effects when sound is of a high frequency. It further enhances the quality of sound when it is of mid-frequency.
One way of addressing the above problems can be found in U.S. Pat. No. 3,804,195, which discloses a loudspeaker enclosure made out of corrugated sheets of material. The corrugated sheets of material include hollow portions. Each of these sheets is joined together in a box-like configuration. Another example can be found in U.S. Pat. No. 4,811,403 which discloses a lightweight loudspeaker enclosure that uses a rigid lightweight honeycombed material in part of the speaker enclosure.
While weight and improved sound performances resulted from the constructions of speaker enclosures found in the above patents, vibrations still remained due to seams joining each of the pieces of the enclosure. Vibrations are induced at the seams and joints reducing overall sound performance of the speakers.
To address this problem, U.S. Pat. No. 5,519,178 discloses a speaker enclosure having a substantially seamless rigid outer skin, a middle sound absorbing layer, and a substantially seamless flexible skin. The outer skin is formed from multiple layers of resin impregnated carbon fiber, the middle sound absorbing layer includes pieces of honeycomb material and the inner layer is formed from multiple layers of resin impregnated fiberglass. The layers of material are arranged in a substantially seamless manner into a mold and then cured by vacuum bagging and heating thereby producing a strong, lightweight speaker enclosure capable of producing overall good quality sound. However, due to the methods used to manufacture the enclosure, the manufacturing method requires precise quality control leading to high manufacturing costs.
There is therefore a need for a durable, light weight speaker enclosure capable of minimizing distortion of sound signals but yet relatively easy and inexpensive to manufacture.
Any discussion of documents, devices, acts or knowledge in this specification is included to explain the context of the invention. It should not be taken as an admission that any of the material forms a part of the state of the art or the common general knowledge in the relevant art in Singapore or elsewhere on or before the priority date of the disclosure and claims herein. All statements as to the date or representation as to the contents of these documents is based on the information available to the applicant and does not constitute any admission as to the correctness of the date or contents of these documents.